Examples of wheeled toy vehicles can be found in U.S. Pat. Nos. 6,725,523, 6,676,476, 6,315,630, 6,074,271, 4,836,819, D487,486, and U.S. Patent Application Publication No. US20050112988. Examples of play sets incorporating magnets can be found in U.S. Pat. Nos. 6,322,415, 6,193,581, 6,056,619, 5,931,714, 3,653,662, and 6,473,27. Examples of play sets incorporating rolling surfaces or sliding surfaces can be found in U.S. Pat. Nos. 5,800,240, 5,542,668, 4,171,090, 4,094,089, 3,721,036, 3,683,514, 3,108,810, 2,999,689, 1,695,310, 758,047, and 719,200. The disclosures of all of the patents, patent applications, and publications recited are incorporated herein by reference.